1. Field of the Invention
The present invention relates to a rotary damper.
2. Description of Related Art
As a conventional rotary damper, there is known one having an oil chamber within a housing which is divided in two by a vane, and generates a damping force by passing operating oil between the two oil chambers when the vane oscillates. This has a shaft supporting the vane to allow oscillation in relation to the housing while the base part of the vane is linked in a fixed state (for example, see FIGS. 2 and 3 in the left-hand column of page 3 of Japanese Unexamined Patent Application, First Publication No. 2001-99208).
The aforementioned conventional rotary damper has the following problem.
That is, in the conventional rotary damper the oil chamber in the housing is divided in two by the vane. However, there is a small gap between the shaft supporting the vane and the housing bearing supporting the shaft due to the two sliding in relation to each other, and this gap provides a location for leakage so that the operating oil in the two chambers within the housing is able to bypass, thus reducing the damping force.